Whenever I go to London, I stop by a little book store called Magma that is packed to the ceiling with only design-related books. It is my dream come true... Possibly also my nightmare considering that I can easily put myself hundreds of dollars in debt. I have come to terms with and accepted the fact that I have a graphic design addiction.
I picked up this little book by KinoDesign a couple years ago. Very cute and well written, including ways to dump a design agency:
"Unpleasant habits
Design agencies are like lovers - at first you think they're sex-on-toast but after a while you notice that they have a number of unpleasant and irritating habits.
Be aware that seriously creative agencies are immune to criticism and will take being fired as nothing more than attention-seeking by the client."